The subject invention is directed toward the valve art and, more particularly, to a flap-type pressure relief or check valve.
Flap-type valves of the type under consideration are commonly used to relieve over-pressure conditions in vehicle compartments and the invention will be described with reference thereto; however, the invention is capable of broader application and could be used in many environments.
One-way, flap-type pressure relief valves are commonly used in vehicle ventilation systems. Typically, they act to relieve over-pressure conditions and allow a controlled flow of air through the passenger compartment. Valves used for this purpose generally comprise a frame which defines a flow passage and one or more internal valve seats. The valve elements comprise flexible flaps that are joined to the frame along one peripheral edge and overlie the seat or seats. When over-pressure conditions occur on one side, the flaps move away from the seats and allow flow through the frame. Upon upstream and downstream balanced pressure or downstream over-pressure, the flaps engage the seats and block reverse flow.
Typical valves of the type under consideration are illustrated in U.S. patents to Ikeda, et al. U.S. Pat. No. 5,167,574; Garries, et al. U.S. Pat. No. 4,899,647; Hagenah U.S. Pat. No. 4,667,578; Kraus, et al. U.S. Pat. No. 5,263,895; and Clough U.S. Pat. No. 5,105,845. In the valves shown in these prior patents, a variety of different systems are used to join the valve flaps to the frame. These systems vary from inserted tabs to bolts, rivets, and heat welded plastic pins and plates. In each case, however, the time required to install the flaps is somewhat excessive. In addition, and more importantly, the flap elements often do not "float" properly relative to the seat opening because of the nature of the resulting clamped connection. Further, many of the prior connections have unsealed connector openings through the frame which result in undesired air infiltration.
As can be seen from the foregoing, a need exists for a more satisfactory system and arrangement for joining the valve flap elements in their mounted position on the frame.